1. Global and U.S. Tuberculosis Epidemiology and Principles of Control
Philip LoBue, MD
Associate Director for Science
Division of Tuberculosis Elimination
National Center for HIV, Viral Hepatitis, STD, and TB Prevention
Centers for Disease Control and Prevention
SAFER HEALTHIER PEOPLE

2. Outline Global epidemiology U.S. epidemiology
U.S. principles of control
Global TB control strategy

3. Global Importance of TB
Top 10 Global Causes of Death (2004)

4. Global Epidemiology

5. Global TB Burden: 2009 WHO Estimates (1)
9.4 million new cases
Rate 137 per 100,000
1.7 million deaths
85% of cases are in Southeast Asia, Africa and Western Pacific
11% of TB cases are HIV-infected
Africa accounts for 80% of HIV-infected cases

6. Global TB Burden: 2009 WHO Estimates (2)
22 high-burden countries account for 81% of cases
Five countries with highest incidence
India (2 million)
China (1.3 million)
South Africa (490 thousand)
Nigeria (460 thousand)
Indonesia (430 thousand)

9. Global TB Trends Incident cases slowly increasing
Incidence rate is slowly decreasing (about 1%) per year
Population increasing faster than TB cases
Mortality also decreasing (about 1/3 since 1990)

10. Drug-Resistant TB
Multidrug-resistant (MDR) TB: resistant to isoniazid and rifampin
Extensively drug-resistant (XDR) TB: MDR TB plus resistance to a fluoroquinolone and any second-line injectable (amikacin, kanamycin, capreomycin)

11. Mechanisms of Drug-Resistant TB
Primary: transmission of drug resistant strain from one person to another
Secondary (acquired): susceptible strain becomes resistant because of improper treatment

12. Global MDR TB Estimates: 2008
New cases MDR TB: 440,000
3.3% of all new cases
50% of new MDR TB cases are in China and India
Highest prevalence in Eastern Europe and Central Asia
150,000 deaths from MDR TB
Much higher in retreatment cases (acquired)
As high as 61% in some countries

14. Global XDR TB Estimates: 2008
5.4% of MDR TB cases
Has been reported in 69 countries
Estimates based on very limited data

16. U.S. Epidemiology

17. Historical Trends in TB, 1953-2009
TB resurgence 1980s-1990s
Reported Cases
1953
Year
2009

18. Reported TB Cases* United States, 1982–2009
Resurgence
National response
No. of Cases
Year
*Updated as of July 1, 2010.

19. Factors Associated with Resurgence of TB in 1980s-1990s
HIV epidemic
Poverty and homelessness
Drug abuse
Migration from high prevalence countries
Emergence of drug-resistant TB
Decline of HCW expertise
Decline of public health infrastructure

20. TB Morbidity United States, 2003–2009
Year No Rate*
2003
14,836
5.1
2004
14,499
4.9
2005
14,064
4.8
2006
13,734
4.6
2007
13,280
4.4
2008
12,906
4.2
2009
11,545
3.8
*Cases per 100,000, updated as of July 1, 2010.

21. TB Case Rates,* United States, 2009
D.C.
< 3.5 (year 2000 target)
3.6–3.8
> 3.8 (national average)
*Cases per 100,000.

22. TB Case Rates* by Age Group United States, 1993–2009
Cases per 100,000
Age Group (years)
*Updated as of July 1, 2010.

23. Reported TB Cases by Age Group, United States, 2009
<15 yrs
(6%)
>65 yrs
(20%)
15–24 yrs
(11%)
45–64 yrs
(30%)
25–44 yrs (34%)

24. TB Case Rates by Age Group and Sex, United States, 2009
Cases per 100,000

25. TB Case Rates by Race/Ethnicity* United States, 1993–2009**
Cases per 100,000
White
Black or African-American
Hispanic
American Indian/Alaska Native
Asian/Pacific Islander
*All races are non-Hispanic. In 2003, Asian/Pacific Islander category includes persons who reported race as Asian only and/or Native Hawaiian or Other Pacific Islander only. **Updated as of July 1, 2010.

26. Reported TB Cases by Race/Ethnicity* United States, 2009
White
(16%)
Asian
(28%)
Native Hawaiian or
Other Pacific Islander (1%)
American Indian or
Alaska Native (1%)
Hispanic or Latino
(29%)
Black or
African-American
(25%)
*All races are non-Hispanic. Persons reporting two or more races accounted for less than 1% of all cases.

27. Number of TB Cases in U. S. -born vs
Number of TB Cases in U.S.-born vs. Foreign-born Persons United States, 1993–2009*
No. of Cases
*Updated as of July 1, 2010.

28. Trends in TB Cases in Foreign-born Persons, United States, 1989–2009*
No. of Cases
Percentage
*Updated as of July 1, 2010.

29. Reported TB Cases by Origin and Race/Ethnicity,* United States, 2009
U.S.-born
Foreign-born**
American Indian or Alaska Native (2%)
White (5%)
Hispanic or Latino (19%)
Hispanic or Latino (36%)
Native Hawaiian/
Other Pacific
Islander (<1%)
Asian (44%)
Black or African American (42%)
White (32%)
Black or African
American (14%)
Asian (3%)
*All races are non-Hispanic. Persons reporting two or more races accounted for less than 1% of all cases.
**American Indian or Alaska Native and Native Hawaiian or Other Pacific Islander accounted for less than 1% of foreign-born cases and are not shown.

30. Percentage of TB Cases Among Foreign-born Persons, United States*
1999
2009 DC DC
>50%
25%–49%
<25%
*Updated as of July 1, 2010.

31. TB Case Rates in U. S. -born vs
TB Case Rates in U.S.-born vs. Foreign-born Persons United States, 1993–2009*
Cases per 100,000
*Updated as of July 1, 2010.

32. Countries of Birth of Foreign-born Persons Reported with TB United States, 2009
Mexico
(23%)
Other
Countries
(38%)
Philippines
(12%)
Haiti
(3%)
India
(8%)
Guatemala
(3%)
China
(5%)
Vietnam
(8%)

33. Percent of Foreign-born with TB by Time of Residence in U. S
Percent of Foreign-born with TB by Time of Residence in U.S. Prior to Diagnosis, 2009
* Foreign-born TB patients for whom information on length of residence in the U.S. prior to diagnosis is unknown or missing.

34. Primary MDR TB United States, 1993–2009*
No. of Cases
Percentage
*Updated as of July 1, 2010.
Note: Based on initial isolates from persons with no prior history of TB.
MDR TB defined as resistance to at least isoniazid and rifampin.

35. Primary MDR TB in U. S. -born vs
Primary MDR TB in U.S.-born vs. Foreign-born Persons, United States, 1993–2009*
% Resistant
*Updated as of July 1, 2010.
Note: Based on initial isolates from persons with no prior history of TB.
MDR TB defined as resistance to at least isoniazid and rifampin.

36. XDR TB Case Count defined on Initial DST† by Year, 1993–2009*
Year of Diagnosis
†Drug susceptibility test.
*Reported incident cases as of July 1, 2010.
Extensively drug-resistant TB (XDR TB) is defined as resistance to isoniazid and rifampin,
plus resistance to any fluoroquinolone and at least one of three injectable second-line anti-TB drugs.

37. Estimated HIV Coinfection in Persons Reported with TB, United States, 1993–2009*
*Updated as of July 1, 2010.
Note: Minimum estimates based on reported HIV-positive status
among all TB cases in the age group.

38. Associated Conditions for 2009 TB Cases
HIV infected: 6.1%
Homelessness: 5.3%
Correction facility: 4.2%
Injection drug use: 1.4%
Non-injection drug use: 7.8%
Excess alcohol use: 13.0%

39. Other Associated Conditions Not Currently Available in U. S
Other Associated Conditions Not Currently Available in U.S. Surveillance Data
Organ transplantation
Chronic renal failure/dialysis
Diabetes melitus
Treatment with TNF-α antagonists
Treatment with glucocorticoids
Silicosis
Head and neck cancer
Cigarette smoking

40. Principles of TB Control in the United States

41. How is TB Transmitted?
Airborne: droplet nuclei containing TB bacilli are coughed into the air by a person with active TB and inhaled by susceptible host
cough
TB bacteria
healthy lung
TB patient

42. Pathogenesis of TB < 30% 5-10% Exposure Primary Infection LTBI
Active TB

43. Pathogenesis of TB <10% Uninfected Active TB <30% LTBI
Exposed

44. Interventions to Control Spread of TB
2) “Window prophylaxis”
(reserved for high-risk persons: HIV, young children)
3) LTBI treatment ( preventive therapy)
Exposure
Primary
Infection
LTBI
Active TB
1) Isolate and treat active cases

45. U.S. TB Control Priorities
Diagnose and treat all persons with active TB
Isolate until no longer infectious
Conduct contact investigations of persons with infectious TB
Detect secondary cases
Detect newly infected persons and treat for LTBI
Targeted testing and treatment of persons with LTBI at risk for progression to active TB

47. Global TB Control Strategy

48. Core Strategy: DOTS Developed for low-income, high-burden countries
Focused on detection and treatment of most infectious cases
Use of smear microscopy and standardized treatment regimens
Culture and drug-susceptibility testing not routinely done
Has limitations especially for HIV/TB and MDR TB

49. Revised Stop TB Strategy
Expand and enhance high quality DOTS
Scaling up of integrated TB/HIV activities (e.g., intensified case find, preventive therapy, antiretroviral therapy)
Scaling up of MDR TB diagnosis and treatment
Strengthen infection control measures
Address needs of TB contacts
Implementation is highly variable from country to country

50. Questions?